Rename the aura_shell namespace to ash

ash/shell_window_ids.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_SHELL_WINDOW_IDS_H_
 #define ASH_SHELL_WINDOW_IDS_H_
 #pragma once
 
 // Declarations of ids of special shell windows.
 
-namespace aura_shell {
+namespace ash {
 
 namespace internal {
 
 // The desktop background window.
 const int kShellWindowId_DesktopBackgroundContainer = 0;
 
 // The container for standard top-level windows.
 const int kShellWindowId_DefaultContainer = 1;
 
 // The container for top-level windows with the 'always-on-top' flag set.
@@ skipping 12 matching lines @@
 const int kShellWindowId_LockModalContainer = 6;
 
 // The container for the status area.
 const int kShellWindowId_StatusContainer = 7;
 
 // The container for menus and tooltips.
 const int kShellWindowId_MenusAndTooltipsContainer = 8;
 
 }  // namespace internal
 
-}  // namespace aura_shell
+}  // namespace ash
 
 
 #endif  // ASH_SHELL_WINDOW_IDS_H_